The present invention relates to a system, an apparatus and a method for multi-carrier transmission which in particular use a bit allocation switching system and a FDM (frequency division multiplexing) system and implements the data transmission using multi-carrier under the noise environment that the changing timing of noise level is known.
Recently, an xDSL (digital subscriber line) technology has been focused on, by which the high-speed transmission of a few megabits/second becomes possible using a metallic cable, such as a loop. In this, x of the xDSL means any of the various types of DSL and x has an alphabet such as A, S, V and H depending on its technology. In this technology, an ADSL (asymmetric digital subscriber line) technology has been highly focused on. This ADSL has different transmission speeds between upstream and downstream directions and this asymmetrical nature is suitable for the access for Internet.
This ADSI, apparatus uses a named DMT (discrete multi-tone) system as a MODEM (modulator-demodulator), and converts digital signals to analog signals and transmits the converted signals. The DMT system implements the modulation applying a QAM (quadrature amplitude modulation) for 256 carriers and the modulated carriers are multiplexed using an IFFT (inverse fast Fourier transform) and are transmitted. The receiving side extracts each carrier from the multiplexed signals using a FFT (fast Fourier transform) and implements the demodulation to signals modulated QAM, with this, the high-speed transmission becomes possible.
However, more over 4 million loops of an ISDN (integrated services digital network) being a TCM (time compression multiplexing) system have been installed in Japan. At the case that the loop for the ADSL is installed adjacent to the loop for the ISDN, a cross-talk noise making the communication speed of the ADSL loop lessen occurs effected by the ISDN loop. In this case, it is possible that the loop for ASDL is separately installed from the loop for ISDN, not to be installed in the same bundle of cable. However, it is too big for an operator to bear the cost. Therefore, it is desirable to establish a transmission method that can secure the transmission capacity not influenced by the cross-talk noise caused in the same batch of the loops for ISDN and the loops for ASDL.
FIG. 1 is a cross-talk noise diagram showing a cross-talk noise generated in the ADSL apparatus caused by the ISDN line. Referring to FIG. 1, the cross-talk noise generated in the ADSL apparatus which used the adjacent line to the ISDN line using the TCM system is explained. In FIG. 1, the cross-talk noise generated in an ATU-R (ADSL transceiver unit, remote terminal end) caused by the data transmission of the TCM-ISDN loop is shown, at the time when the downstream data transmission is implemented in the ADSL loop.
In the TCM-ISDN loop, the data transmission of upstream and downstream directions is implemented alternately every 1.25 milliseconds. At the time when the ADSL loop implements downstream data transmission and the TCM-ISDN loop implements upstream data transmission, a high power signal before attenuation of the TCM-ISDN influences an attenuated signal of the ADSL loop and a NEXT (near end cross-talk) is generated at the ATU-R. At the time when the ADSL loop implements downstream data transmission and the TCM-ISDN loop implements downstream data transmission, a signal of the TCM-ISDN influences an attenuated signal of the ADSL loop and a FEXT (far end cross-talk) is generated at the ATU-R. The same kind of influences is generated at an ATU-C (ADSL transceiver unit, central office end).
FIG. 2 is a noise amount diagram showing the amount of the cross-talk noise in FIG. 1. As shown in FIG. 2, the amount of noise generating at the NEXT is larger than that at the FEXT. The reason why this occurs is that the high power signal before attenuation of the TCM-ISDN influences the attenuated signal of the ADSL loop. Focusing on this difference of the amount of noise, a system is proposed, this system transmits data by switching the amount of data to be transmitted between at the time generated NEXT and the FEXT. This system is called a DBM (dual bit-map) and transmits large data at the time generated the FEXT that the amount of noise is small and transmits small data at the time generated the NEXT that the amount of noise is large, as shown in FIG. 2.
As mentioned above, at the ADSL apparatus whose loop is adjacent to the TCM-ISDN loop, the amount of noise changes cyclically, therefore SNR (signal to noise ratio) of each carrier is measured in each of upstream and downstream directions, and the bit allocation is obtained corresponding to this measured SNR.
FIG. 3 is a block diagram showing the structure of a conventional ADSL apparatus. Referring to FIG. 3, the structure of the conventional ADSL apparatus is explained.
The transmitting section of the ATU-C 300 includes a rate converter 301 in which data transmitted in a constant speed from the external equipment are temporarily stored, a mapping section 302 which switches the bit allocation and transmission power allocation of each carrier corresponding to the changing timing of noise level and implements the bit allocation and transmission power allocation to each carrier, an IFFT (inverse fast Fourier transform) 303 which implements the modulating and multiplexing in each carrier for multi-point QAM (quadrature amplitude modulation) signals being the output of this mapping, and a DAC (digital to analog converter) 304 which converts this digital mutiplexed output to a downstream analog signal and transmits the analog signal.
The receiving section of the ATU-C 300 includes an ADC (analog to digital converter) 305 which converts analog signals transmitted from an ATU-R 400 to digital signals, a FFT (fast Fourier transform) 306 which implements the fast Fourier transform for these digital signals, a demapping section 307 which switches the bit allocation and transmission power allocation of each carrier corresponding to the changing timing of noise level and demodulates the transmitted signals, and a rate converter 308 which adjusts the change of the amount of data transmission caused by the change of bit allocation and transfers the data to the external equipment in a constant speed.
The transmitting section of the ATU-R 400 includes a rate converter 401 in which data transmitted in a constant speed from the external equipment are temporarily stored, a mapping section 402 which switches the bit allocation and transmission power allocation of each carrier corresponding to the changing timing of noise level and implements the bit allocation and transmission power allocation to each carrier, an IFFT (inverse fast Fourier transform) 403 which implements the modulating and multiplexing in each carrier for multi-point QAM (quadrature amplitude modulation) signals being the output of this mapping, and a DAC (digital to analog converter) 404 which converts this digital multiplexed output to an upstream analog signal and transmits the analog signal.
The receiving section of the ATU-R 400 includes an ADC (analog to digital converter) 408 which converts analog signals transmitted from the ATU-C 400 to digital signals, a FFT (fast Fourier transform) 407 which implements the fast Fourier transform for these digital signals, a demapping section 406 which switches the bit allocation and transmission power allocation corresponding to the changing timing of noise level and demodulates the transmitted signals, and a rate converter 405 which adjusts the change of the amount of data transmission caused by the change of bit allocation and transfers the data to the external equipment in a constant speed.
The ATU-C 300 further includes a pseudo-random signal generating section 310 and a bit and power allocation calculating section 312 and the ATU-R 400 further includes a pseudo-random signal generating section 409 and a bit and power allocation calculating section 410. FIG. 4 is a block diagram showing the structure of a bit and power allocation calculating section 312 of the ATU-C 300. FIG. 5 is a block (diagram showing the structure of a bit and power allocation calculating section 410 of the ATU-R 400.
At the time when the ISDN implements downstream transmission, the NEXT is generated in the ATU-C 300 and the FEXT is generated in the ATU-R 400. And at the time when the ISDN implements upstream transmission, the FEXT is generated in the ATU-C 300 and the NEXT is generated in the ATU-R 400.
Under this noise environment, in order to secure the data transmission capacity, pseudo-random signal generating sections 310 and 409 generate the pseudo-random signals being the data which are composed of predetermined pseudo-random orders and are allocated in sequence, to each carrier using for data transmission. And the pseudo-random signal generating sections 310 and 409 output the generated pseudo-random signals to the IFFT 303 and 403 respectively and after this, the outputs from the IFFT are outputted to each counter remote terminal.
Bit and power allocation calculating sections 312 and 410 calculate the bit allocation allocating to each carrier for data transmission and the transmission power allocation using in each carrier by using the pseudo-random signals generated at the pseudo-random signal generating sections 409 and 310 of the counter remote terminals, for the time of the NEXT and FEXT.
The calculated bit allocation and transmission power allocation is memorized in the demapping section of the own end and is memorized in the demapping section of the counter remote terminal respectively.
A processing flow calculating the above mentioned bit allocation and transmission power allocation is explained in detail. The same processing is implemented for the ATU-C 300 and the ATU-R 400, therefore only the processing to calculate the downstream bit allocation and transmission power allocation is explained.
At the training period when the bit allocation allocating to carrier and the transmission power allocation using for each carrier is calculated, the pseudo-random signal generating section 310 modulates the amplitude of each carrier using for data transmission to the amplitude corresponding to the order of bits of prescribed data allocated by the predetermined pseudo-random order and outputs to the IFFT 303.
The IFFT 303 implements the inverse fast Fourier transform to each carrier modulated the amplitude and outputs the voltage value added each carrier and expressed in digital form. The DAC 304 converts the voltage value of the digital form to the analog signal being the actual value and outputs to the loop.
The ATU-R 400 converts the analog signals transmitted from the ATU-C 300 to the voltage value expressed in digital form at the ADC 408. After this, the voltage value in digital form is implemented the fast Fourier transform at the FFT 407 and each carrier modulated its amplitude is taken out.
Each carrier taken out at the FFT 407 is outputted to the bit and power allocation calculating section 410.
In the bit and power allocation calculating section 410, the plural SNR values of each carrier are calculated at the both time of the NEXT generated and the FEXT generated in a downstream SNR evaluating section 414 and the average value of SNR of each carrier is calculated. FIG. 6A is a diagram showing the average values of the SNR at the NEXT generated and the FEXT generated, which are evaluated at the downstream SNR evaluating section 414. The downstream SNR evaluating section 414 holds the calculated average value of SNR at the time of the NEXT generated in a NEXT SNR 415 and the calculated average value of SNR at the time of the FEXT generated in a FEXT SNR 415 respectively.
A bit and power allocation table calculating section 416 calculates the bit allocation and transmission power allocation of each carrier in every noise level by the measured average value of SNR of each carrier, and the calculated bit allocation and transmission power allocation is outputted to the demapping section 406 and is memorized in the demapping section 406 and is also outputted to the mapping section 402. FIG. 6B is a diagram showing the determining state of the bit allocation of each carrier corresponding to the average value of SNR evaluated at the downstream SNR evaluating section 414.
At the training period when the bit allocation allocating to the carrier used for data transmission and the transmission power allocation using for each carrier is calculated, the mapping section 402 allocates the information of the bit allocation and transmission power allocation calculated at the bit and power allocation calculating section 410 to the predetermined carrier in the predetermined number of bits, and outputs the allocated result to the IFFT 403.
The IFFT 403 implements the inverse fast Fourier transform to the predetermined carrier transmitted from the mapping section 402 and outputs the voltage value expressed in digital form. The DAC 404 generates the analog signal being an actual voltage value from the voltage value expressed in digital form and outputs the analog signal to the loop.
The ATU-C 300 converts the analog signal transmitted from the ATU-R 400 to the voltage value expressed in digital form at the ADC 305. The FFT 306 implements the fast Fourier transform for the voltage value in digital form and takes out each carrier modulated its amplitude.
The demapping section 307 takes out the information of the bit allocation and transmission power allocation from the predetermined carrier allocated the designated number of bits and outputs the taken out information of the bit allocation and transmission power allocation to the mapping section 302 and the information is memorized in the mapping section 302.
Using the two kinds of bit allocation and transmission power allocation calculated by the above mentioned processing, the mapping sections 302 and 402 select the bit allocation and transmission power allocation corresponding to the noise level generated at the time of data transmission and implements the bit allocation and transmission power allocation for each carrier. The demapping sections 307 and 406 take out the data allocated to the carrier by using the same bit allocation and transmission power allocation that the bit allocation and transmission power allocation is implemented at the counter remote terminal corresponding to the noise level.
Furthermore, the ATU-C 300 provides a tone synchronized with noise generating section 311 and the ATU-R 400 provides a clock detecting section 411 and a bit and power allocation selecting section 412.
The clock in the ATU-C 300 is a clock synchronizing with to the changing timing of noise level and, in this case, the changing timing of noise level is known. For example, at the case that the noise is a cross-talk noise from the TCM-ISDN, the NEXT and the FEXT are generated every 1.25 milliseconds, therefore the SNR of each carrier also changes every 1.25 milliseconds. Therefore, at the transmitting section of the ATU-C 300, by receiving the clock by which the amplitude of the predetermined carrier changes in a 1.25 milliseconds cycle synchronized with the changing timing of noise level, the clock must be transmitted to the receiving section of the ATU-R 400. Accordingly, the tone synchronized with noise generating section 311 generates a tone signal synchronized with noise made the signal level change by synchronizing with the clock and transmits the tone synchronized with noise to the ATU-R 400. In the more detailed explanation, the tone synchronized with noise generating section 311 makes the amplitude of the predetermined carrier change with the synchronization of the changing timing of noise level, using the clock synchronizing with the changing timing of noise level, and outputs to the IFFT 303.
A clock detecting section 411 detects the changing timing of noise level by the change of amplitude of the designated carrier, in this, the changing timing is taken out by a FFT 407. The detected changing timing of noise level is transmitted to the bit and power allocation selecting section 412.
The bit and power allocation selecting section 412 recognizes the changing timing of noise level by the information from the clock detecting section 411 and selects one from the memorized two kinds of bit allocation and transmission power allocation in the mapping section 402 and designates the bit allocation and transmission power allocation to use the implementation of data transmission corresponding to the noise level. And the bit and power allocation selecting section 412 also selects one from the memorized two kinds of bit allocation and transmission power allocation in the demapping section 406 and in order to use for demodulation, designates the same bit allocation and transmission power allocation used by corresponding to the noise level at the ATU-C 300.
FIG. 7 is a hyperframe structure diagram composed of 345 symbols. The left side symbols from dotted line A shown in FIG. 7 have a low cross-talk noise from the ISDN loop (FEXT generated) and are able to allocate many bits to a carrier. The symbols between the dotted lines A and B shown in FIG. 7 have a high cross-talk noise from the ISDN loop (NEXT generated) and are able to allocate only a few bits to a carrier. The transmission is started from the symbol 0 (zero) synchronizing with the FEXT generating timing from the ISDN, as shown in FIG. 7, according to this, the receiving timing of the 345th symbol and the switching timing of cross-talk noise from the ISDN are synchronized. Therefore, from the next 346th symbol, the transmission of symbols is able to be implemented by synchronizing with the FEXT generating timing from ISDN. The bit and power allocation selecting section 412 memorizes which bit allocation and transmission power allocation should be used every transmission order of symbols, from the two kinds of bit allocation and transmission power allocation.
The ATU-C 300 provides an echo canceler 313 and the ATU-R 400 provide an echo canceler 413. FIG. 8 is a frequency band diagram using for data transmission by an echo canceler system. As shown in FIG. 8, in order to increase the transmission capacity, a part of the frequency band using for upstream and downstream data transmission is overlapped. Therefore, the echo canceler is provided to cancel the influence from reflection.
The operation of the IFFT is explained in more detail. The signals from the pseudo-random signal generating section, the tone synchronized with noise generating section and the mapping section are outputted to the IFFT. However these signals are not inputted at the same time. That is, the IFFT implements the inverse fast Fourier transform for signal inputted in different time and outputs to the DAC.
The mentioned above each equipment is controlled by a sequencer which is not described in diagrams. By the control of this sequencer, at the predetermined signal outputting timing, the pseudo-random signal generating section and the tone synchronized with noise generating section output signals to the IFFT. The IFFT recognizes that from which equipment next signal is inputted, by the operation of sequencer.
However, there is a problem that using an echo canceler makes the structure of apparatus complex and makes the apparatus high cost.
Therefore, utilizing the characteristics of bitmap system and securing the capacity of data transmission, a simply structured transmission system is desirable.
It is therefore an object of the present invention to provide a system, an apparatus and a method for multi-carrier transmission which secure the transmission capacity and can also have simple structure under the noise environment that the changing timing of noise level is known.
According to a first aspect of the present invention, for achieving the above mentioned objects, the present invention is a system for multi-carrier transmission which implements data transmission using the multi-carrier between a first communication equipment and a second communication equipment interactively under the noise environment that the changing timing of noise level is known.
Said first communication equipment switches bit rates of the data transmission using a first frequency band corresponding to the changing timing of noise level and comprises a first transmitting means for transmitting the data to said second communication equipment.
Said second communication equipment switches bit rates of the data transmission using a second frequency band corresponding to the changing timing of noise level and comprises a second transmitting means for transmitting the data to said first communication equipment.
Said system for multi-carrier transmission makes the bit rate with which said second transmitting means implements the data transmission of a second direction from said second communication equipment to said first communication equipment using said second frequency band higher than the bit rate with which said first transmitting means implements the data transmission of the first direction from said first communication equipment to said second communication equipment using said first frequency band, during the period that the noise generated at the data transmission of said first direction from said first communication equipment to said second communication equipment is large.
According to a second aspect of the present invention, in the first aspect, said system for multi-carrier transmission makes the bit rate with which said first transmitting means implements the data transmission of said first direction using said first frequency band higher than the bit rate with which said second transmitting means implements the data transmission of said second direction using said second frequency band, during the period that the noise generated at the data transmission to said second direction is large.
According to a third aspect of the present invention, in the first aspect, said first transmitting means implements the data transmission using the carrier of said first frequency band, by making the bit rate of the data transmission implementing during the period that the noise generated at the data transmission to said second direction is large higher than the bit rate of the data transmission implementing during the period that the noise generated at the data transmission to said first direction is large.
According to a fourth aspect of the present invention, in the first aspect, said second transmitting means implements the data transmission using the carrier of said second frequency band, by making the bit rate of the data transmission implementing during the period that the noise generated at the data transmission to said first direction is large higher than the bit rate of the data transmission implementing during the period that the noise generated at the data transmission to said second direction is large.
According to a fifth aspect of the present invention, in the first aspect, said first transmitting means provides a first memorizing means which memorizes the bit allocation allocating to each carrier of said first frequency band and the transmission power allocation using for each carrier of said first frequency band which transmit the data to said first direction during the period that the noise generated at the data transmission to said first direction is large and memorizes the bit allocation allocating to each carrier of said first frequency band and the transmission power allocation using for each carrier of said first frequency band which transmit the data to said first direction during the period that the noise generated at the data transmission to said second direction is large and a first modulating means which reads out the two kinds of bit allocation and transmission power allocation from said first memorizing means and allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, by making the bit rate during the period that the noise generated at the data transmission to said second direction is large higher than the bit rate during the period that the noise generated at the data transmission to said first direction is large, corresponding to the changing timing of noise level.
According to a sixth aspect of the present invention, in the first aspect, said second transmitting means provides a second memorizing means which memorizes the bit allocation allocating to each carrier of said second frequency band and the transmission power allocation using for each carrier of said second frequency band which transmit the data to said second direction during the period that the noise generated at the data transmission to said first direction is large and memorizes the bit allocation allocating to each carrier of said second frequency band and the transmission power allocation using for each carrier of said second frequency band which transmit the data to said second direction during the period that the noise generated at the data transmission to said second direction is large, and a second modulating means which reads out the two kinds of bit allocation and transmission power allocation from said second memorizing section and allocates the bit allocation and transmission power allocation to each carrier of said second frequency band, by making the bit rate during the period that the noise generated at the data transmission to said first direction is large higher than the bit rate during the period that the noise generated at the data transmission to said second direction is large, corresponding to the changing timing of noise level.
According to a seventh aspect of the present invention, in the first aspect, said first communication equipment provides a third memorizing means which memorizes the bit allocation allocating to each carrier of said second frequency band and transmission power allocation using for each carrier of said second frequency band transmitted from said second communication equipment during the period the noise generated at the data transmission to said first direction and memorizes the bit allocation allocating to each carrier of said second frequency band and transmission power allocation using for each carrier of said second frequency band transmitted from said second communication equipment during the period the noise generated at the data transmission to said second direction, and a first receiving means which includes a first demodulating means that reads out the two kinds of bit allocation and transmission power allocation from said third memorizing section and demodulates the data transmitted from said second communication equipment, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated at said second communication equipment corresponding to the changing timing of noise level.
According to an eighth aspect of the present invention, in the first aspect, said second communication equipment provides a fourth memorizing means which memorizes the bit allocation allocating to each carrier of said first frequency band and transmission power allocation using for each carrier of said first frequency band transmitted from said first communication equipment during the period the noise generated at the data transmission to said first direction and memorizes the bit allocation allocating to each carrier of said first frequency band and transmission power allocation using for each carrier of said first frequency band transmitted from said first communication equipment during the period the noise generated at the data transmission to said second direction, and a second receiving means which includes a second demodulating means that reads out the two kinds of bit allocation and transmission power allocation from said fourth memorizing means and demodulates the data transmitted from said first communication equipment, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated at said first communication equipment corresponding to the changing timing of noise level.
According to a ninth aspect of the present invention, in the seventh aspect, said second communication equipment provides a second pseudo-random signal generating means which generates pseudo-random signals allocated in sequence the data being predetermined pseudo-random order to each carrier of said second frequency band using for the data transmission to said second direction and outputs to said second transmitting means. And said first communication equipment provides a first SNR (signal to noise ratio) calculating means which calculates the two kinds of average SNR value of each carrier of said second frequency band using for the data transmission of said second direction used the pseudo-random signals received at said first receiving means, at the period that the noise generated at the data transmission to said second direction is large and at the period that the noise generated at the data transmission to said first direction is large, and a first bit and power allocation calculating means which calculates the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said second frequency band, by using said average SNR value of each carrier calculated at said first SNR calculating means, at the period that the noise generated at the data transmission to said second direction is large and at the period that the noise generated at the data transmission to said first direction is large. And said third memorizing means memorizes the information of the two kinds of bit allocation and transmission power allocation calculated at said first bit and power allocation calculating means and also outputs them to said first modulating means, and said first transmitting means outputs them to said second communication equipment. And said first modulating means, at the training period that evaluates the bit allocation and transmission power allocation allocating to each carrier, allocates the information of the two kinds of the bit allocation and transmission power allocation calculated at said first bit and power allocation calculating means to the designated carrier in designated number of bits each. And said second communication equipment receives said designated carrier from said first communication equipment at said second receiving means and also takes out the information of said two kinds of bit allocation and transmission power allocation from said designated carrier at said second demodulating means and memorizes the information of the taken out two kinds of bit allocation and transmission power allocation at said second memorizing means.
According to a tenth aspect of the present invention, in the eighth aspect, said first communication equipment provides a first pseudo-random signal generating means which generates pseudo-random signals allocated in sequence the data being predetermined pseudo-random order to each carrier of said first frequency band using for the data transmission to said first direction and outputs to said first transmitting means. And said second communication equipment provides a second SNR (signal to noise ratio) calculating means which calculates the two kinds of average SNR value of each carrier of said first frequency band using for the data transmission of said first direction used the pseudo-random signals received at said second receiving means, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, and a second bit and power allocation calculating means which calculates the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said first frequency band, by using said average SNR value of each carrier calculated at said second SNR calculating means, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large. And said fourth memorizing means memorizes the information of the two kinds of bit allocation and transmission power allocation calculated at said second bit and power allocation calculating means and also outputs them to said second modulating means, and said second transmitting means outputs them to said first communication equipment. And said second modulating means, at the training period that evaluates the bit allocation and transmission power allocation allocating to each carrier, allocates the information of the two kinds of the bit allocation and transmission power allocation calculated at said second bit and power allocation calculating means to the designated carrier in designated number of bits each. And said first communication equipment receives said designated carrier from said second communication equipment at said first receiving means and also takes out the information of said two kinds of bit allocation and transmission power allocation from said designated carrier at said first demodulating means and memorizes the information of the taken out the two kinds of bit allocation and transmission power allocation at said first memorizing means.
According to an eleventh aspect of the present invention, in the ninth aspect, said first communication equipment provides a first filter means which removes side lobes generated at said second frequency band from the carrier of said first frequency band having the data, at the back position of said first transmitting means, and a second filter means which removes side lobes generated at said first frequency band from the carrier of said second frequency band transmitted from said second communication equipment, at the front position of said first receiving means.
According to a twelfth aspect of the present invention, in the ninth aspect, said second communication equipment provides a third filter means which removes side lobes generated at said first frequency band from the carrier of said second frequency band having the data, at the front position of said second transmitting means, and a fourth filter means which removes side lobes generated at said second frequency band from the carrier of said first frequency band transmitted from said first communication equipment, at the back position of said second receiving means.
According to a thirteenth aspect of the present invention, in the eighth aspect, said first communication equipment provides a clock signal generating means which generates the clock signal changed the amplitude of the designated carrier, by synchronizing with the changing timing of noise level and transmits said clock signal from said clock signal generating means to said second communication equipment using said first transmitting means, said second communication equipment comprises a clock detecting means which detects the changing timing of noise level from the change of the amplitude of said clock signal received from said second receiving means, transmitted from said first communication equipment, said second communication equipment designates the bit allocation and transmission power allocation using for the implementation of the data transmission corresponding to the noise level, from the two kinds of bit allocation and transmission power allocation memorized at said second memorizing means, to said second modulating means by the changing timing of noise level detected by said clock detecting means, and provides a bit allocation and transmission power allocation selecting means which designates the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation used corresponding to the noise level at said first communication equipment using for the demodulation of the data, from the two kinds of bit allocation and transmission power allocation memorized at said fourth memorizing means, to said second demodulating means.
According to a fourteenth aspect of the present invention, in a system for multi-carrier transmission which implements the data transmission using the multi-carrier between the first communication equipment and the second communication equipment interactively under the noise environment that the changing timing of noise level is known, said first communication equipment provides a first temporarily memorizing means for memorizing the data transmitted from external equipment temporarily, a first memorizing means which memorizes the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the first frequency band transmitting the data, at the period that the noise generated at the data transmission to the first direction being from said first communication equipment to said second communication equipment is large and at the period that the noise generated at the data transmission to the second direction being from said second communication equipment to said first communication equipment is large, a first modulating means which reads out the two kinds of bit allocation and transmission power allocation memorized in said first memorizing means and also reads out the data memorized in said first temporarily memorizing means, and selects the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said first frequency band corresponding to the noise level at the data transmission, and modulates the amplitude of said each carrier to the amplitude corresponding to the selected bit allocation and transmission power allocation and the order of bits of the data allocating to said each carrier, a first IFFT (inverse fast Fourier transform) means which adds up each carrier of said first frequency band modulated the amplitude at said first modulating means and outputs the voltage value expressed in digital form, a transmitting means providing a first DAC (digital to analog converter) means which converts the voltage value expressed in digital form outputted from said first IFFT means to analog signals and outputs to a loop, and a first filter means which removes side lobes generated at said second frequency band by the carrier of said first frequency band outputted to the loop by said first DAC means, and allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, by making the bit rate during the period that the noise generated at the data transmission to said second direction is large higher than the bit rate during the period that the noise generated at the data transmission to said first direction is large, by said first modulating means.
According to a fifteenth aspect of the present invention, in the fourteenth aspect, said second communication equipment provides a second temporarily memorizing means for memorizing the data transmitted from external equipment temporarily, a second memorizing means which memorizes the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the second frequency band transmitting the data, at the period that the noise generated at the data transmission to the first direction is large and at the period that the noise generated at the data transmission to the second direction is large, a second modulating means which reads out the two kinds of bit allocation and transmission power allocation memorized in said second memorizing means and also reads out the data memorized in said second temporarily memorizing means, and selects the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said second frequency band corresponding to the noise level at the data transmission, and demodulates said amplitude of each carrier to the amplitude corresponding to the selected bit allocation and transmission power allocation and said order of bits allocating to each carrier, a second IFFT (inverse fast Fourier transform) means which adds tip each carrier of said second frequency band modulated the amplitude at said second modulating means and outputs the voltage value expressed in digital form, a transmitting means providing a second DAC (digital to analog converter) means which converts the voltage value expressed in digital form outputted from said second IFFT means to analog signals and outputs to a loop, and a third filter means which removes side lobes generated at said first frequency band by the carrier of said second frequency band outputted to the loop by said second DAC means, and allocates the bit allocation and transmission power allocation to each carrier of said second frequency band, by making the bit rate during the period that the noise generated at the data transmission to said first direction is large higher than the bit rate during the period that the noise generated at the data transmission to said second direction is large, by said second modulating means.
According to a sixteenth aspect of the present invention, in the fourteenth aspect, said first communication equipment provides a first ADC (analog to digital converter) means which converts analog signals transmitted from said second communication equipment using the carrier of said second frequency band to the voltage value expressed in digital form, a first FFT (fast Fourier transform) means which implements the fast Fourier transform to said voltage value expressed in digital form from said first ADC means and takes out each carrier whose amplitude is modulated of said second frequency band, a third memorizing means which memorizes the two kinds of the bit allocation allocated to each carrier and transmission power allocation used for each carrier of said second frequency band transmitting from said second communication equipment, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, a first demodulating means which reads out the two kinds of the bit allocation and transmission power allocation from said third memorizing means and takes out the data allocated to each carrier of said second frequency band from said first FFT means, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at said second communication equipment, a receiving means providing a third temporarily memorizing means which temporarily memorizes the data taken out by said first demodulating means, in order to make the output amount of data a constant value, and a second filter means which removes side lobes generated at said first frequency band by each carrier of said second frequency band transmitted from said second communication equipment, at the front position of said receiving means.
According to a seventeenth aspect of the present invention, in the fifteenth aspect, said second communication equipment provides a second ADC (analog to digital converter) means which converts analog signals transmitted from said first communication equipment using the carrier of said first frequency band to the voltage value expressed in digital form, a second FFT (fast Fourier transform) means which implements the fast Fourier transform to said voltage value expressed in digital form from said second ADC means and takes out each carrier whose amplitude is modulated of said first frequency band, a fourth memorizing means which memorizes the two kinds of the bit allocation allocated to each carrier and transmission power allocation used for each carrier of said first frequency band transmitting from said first communication equipment, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, a second demodulating means which reads out the two kinds of the bit allocation and transmission power allocation from said fourth memorizing means and takes out the data allocated to each carrier of said first frequency band from said second FFT means, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at said first communication equipment, a receiving means providing a fourth temporarily memorizing means which temporarily memorizes the data taken out by said second demodulating means, in order to make the output amount of data a constant value, and a fourth filter means which removes side lobes generated at said second frequency band by each carrier of said first frequency band transmitted from said first communication equipment, at the front position of said receiving means.
According to an eighteenth aspect of the present invention, in the seventeenth aspect, said second communication equipment provides a second pseudo-random signal generating means which modulates the amplitude of each carrier of said second frequency band using for the data transmission of said second direction to the amplitude corresponding to the order of bits of the designated data allocating by the predetermined pseudo-random order, and outputs the result to said second IFFT, and said first communication equipment provides a first SNR calculating means which calculates the two kinds of average value of SNR of each carrier of said second frequency band using for the data transmission to said second direction, by using each carrier whose amplitude is modulated of said second frequency band, taken out by said first FFT means, at the period that the noise generated at the data transmission to said second direction is large and at the period that the noise generated at the data transmission to said first direction is large, and a first bit and power allocation calculating means which calculates the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said second frequency band, by using the average value of SNR of said each carrier calculated at said first SNR calculating means, at the period that the noise generated at the data transmission to said second direction is large and at the period that the noise generated at the data transmission to said first direction is large, and the information of the two kinds of bit allocation and transmission power allocation calculated at said first bit and power allocation calculating means is memorized in said third memorizing means and is also outputted to said first modulating means, and is outputted to said second communication equipment, and said first modulating means, at the training period that the bit allocation and transmission power allocation allocating to said each carrier is evaluated, modulates the amplitude of the designated carrier to the amplitude corresponding to the order of bits of the data allocating to each carrier, with this, allocates the information of the two kinds of bit allocation and transmission power allocation calculated at said first bit and power allocation calculating means to said designated carrier in the designated number of bits each and outputs the result to said first IFFT means, and said second communication equipment takes out the information of said two kinds of bit allocation and transmission power allocation from said designated carrier whose amplitude is modulated which is taken out from said second FFT means at said second demodulating means and memorizes the information of the taken out two kinds of bit allocation and transmission power allocation in said second memorizing means.
According to a nineteenth aspect of the present invention, in the seventeenth aspect, said first communication equipment provides a first pseudo-random signal generating means which modulates the amplitude of each carrier of said first frequency band using for the data transmission of said first direction to the amplitude corresponding to the order of bits of the designated data allocating by the predetermined pseudo-random order, and outputs the result to said first IFFT, and said second communication equipment provides a second SNR calculating means which calculates the two kinds of average value of SNR of each carrier of said first frequency band using for the data transmission to said first direction, by using each carrier whose amplitude is modulated of said first frequency band, taken out by said second FFT means, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, and a second bit and power allocation calculating means which calculates the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said first frequency band, by using the average value of SNR of said each carrier calculated at said second SNR calculating means, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, and the information of the two kinds of bit allocation and transmission power allocation calculated at said second bit and power allocation calculating means is memorized in said fourth memorizing means and is also outputted to said second modulating means, and is outputted to said first communication equipment, and said second modulating means, at the training period that the bit allocation and transmission power allocation allocating to said each carrier is evaluated, modulates the amplitude of the designated carrier to the amplitude corresponding to the order of bits of the data allocating to each carrier, with this, allocates the information of the two kinds of bit allocation and transmission power allocation calculated at said second bit and power allocation calculating means to said designated carrier in the designated number of bits each and outputs the result to said second IFFT means, and said first communication equipment takes out the information of said two kinds of bit allocation and transmission power allocation from said designated carrier whose amplitude is modulated which is taken out from said first FFT means at said first demodulating means and memorizes the information of the taken out two kinds of bit allocation and transmission power allocation in said first memorizing means.
According to a twentieth aspect of the present invention, in the seventeenth aspect, said first communication equipment provides a signal synchronized with noise generating means which generates a signal synchronized with noise which makes the amplitude of the designated carrier change, by synchronizing with the changing timing of noise level, and outputs the result to said first IFFT means, and said second communication equipment provides a timing detecting means which detects the changing timing of noise level by the change of the amplitude of said designated carrier taking out from said second FFT means, and a bit and power allocation selecting means which implements the designation of the bit allocation and transmission power allocation using for the data transmission corresponding to the noise level, from the two kinds of bit allocation and transmission power allocation memorized in said second memorizing means, to said second modulating means, by the changing timing of noise level detected by said timing detecting means, and designates the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation used corresponding to the noise level at said first communication equipment from the two kinds of bit allocation and transmission power allocation memorized in said fourth memorizing means, to said second demodulating means using for the demodulation of the data.
According to a twenty first aspect of the present invention, in the first aspect, said first frequency band is a high frequency band and said second frequency band is a low frequency band.
According to a twenty second aspect of the present invention, in the first aspect, said first frequency band is a low frequency band and said second frequency band is a high frequency band.
A system for multi-carrier transmission of the present invention separates the frequency band using for the data transmission to the first direction and the frequency band using for the data transmission to the second direction. During the period that the noise generated at the data transmission to the first direction is large, the bit rate of the transmission to the second direction using the second frequency band is made higher than the bit rate of the transmission to the first direction using the first frequency band. During the period that the noise generated at the data transmission to the second direction is large, the bit rate of the transmission to the first direction using the first frequency band is made higher than the bit rate of the transmission to the second direction using the second frequency band. With this, the present invention can improve the communication performance largely under the noise environment of the changing noise level, securing the compatibility with the existing communication systems using the frequency division system. The frequency bands used for the data transmission to the first direction and the second direction are separated, therefore the mutual cross-talk noise does not exist and a complex apparatus such as an echo canceler is not needed to be installed.
At the first communication equipment, the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data to the first direction, at the period that the noise generated at the data transmission to the first direction is large and the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data to the first direction, at the period that the noise generated at the data transmission to the second direction is large are memorized. The bit allocation to the carrier of the first frequency band is allocated, by making the bit rate at the period that the noise generated at the data transmission to the second direction is large higher than the bit rate at the period that the noise generated at the data transmission to the first direction is large. With this, the transmission capacity to the first direction is secured under the noise environment of the changing noise level.
At the second communication equipment, the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band which transmits the data to the second direction, at the period that the noise generated at the data transmission to the first direction is large and the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band which transmits the data to the second direction, at the period that the noise generated at the data transmission to the second direction is large are memorized. The bit allocation to the carrier of the second frequency band is allocated, by making the bit rate at the period that the noise generated at the data transmission to the first direction higher than the bit rate at the period that the noise generated at the data transmission to the second direction. With this, the transmission capacity to the second direction is secured under the noise environment of the changing noise level.
At the first communication equipment, the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitting from the second communication equipment, at the period that the noise generated at the data transmission to the second direction is large, and the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitting from the second communication equipment, at the period that the noise generated at the data transmission to the first direction is large are memorized. The data transmitted from the second communication equipment are demodulated using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at the second communication equipment from the memorized two kinds of bit allocation and transmission power allocation. With this, even the transmission capacity of the data transmitting from the second communication equipment is changed by the change of noise level, the data can be demodulated at the first communication equipment.
At the second communication equipment, the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band transmitting from the first communication equipment, at the period that the noise generated at the data transmission to the second direction is large, and the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band transmitting from the first communication equipment, at the period that the noise generated at the data transmission to the first direction is large are memorized. The data transmitted from the first communication equipment are demodulated using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the noise cycle changing cyclically at the first communication equipment from the memorized two kinds of bit allocation and transmission power allocation. With this, even the transmission capacity of the data transmitting from the second communication equipment is changed by the change of noise level, the data can be demodulated at the second communication equipment.
At the second communication equipment, the pseudo-random signal allocated in sequence data being the predetermined pseudo-random order is generated to each carrier of the second frequency band using for the data transmission of the second direction and is transmitted to the first communication equipment. At the first communication equipment, the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the second frequency band is calculated by using this pseudo-random signal. With this, the bit allocation and transmission power allocation corresponding to the noise level can be calculated.
At the first communication equipment, the pseudo-random signal allocated in sequence data being the predetermined pseudo-random order is generated to each carrier of the first frequency band using for the data transmission of the first direction and is transmitted to the second communication equipment. At the second communication equipment, the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the first frequency band is calculated by using this pseudo-random signal. With this, the bit allocation and transmission power allocation corresponding to the noise level can be calculated.
According to a twenty third aspect of the present invention, at an apparatus for multi-carrier transmission which implements the data transmission using the multi-carrier under the noise environment that the changing timing of noise level is known, the apparatus for multi-carrier transmission provides a transmitting means which implements the data transmission using each carrier of a first frequency band, by making the bit rate of the data transmission implementing during the period that the noise becomes large at the counter communication equipment higher than the bit rate of the data transmission implementing during the period that the noise becomes large at the apparatus for multi-carrier transmission.
According to a twenty fourth aspect of the present invention, in the twenty third aspect, said first transmitting means provides a first memorizing means which memorizes the bit allocation allocating to each carrier of said first frequency band and the transmission power allocation using for each carrier of said first frequency band which transmit the data during the period that said noise is large at said apparatus for multi-carrier transmission and memorizes the bit allocation allocating to each carrier of said first frequency band and the transmission power allocation using for each carrier of said first frequency band which transmit the data during the period that said noise is large at said counter communication equipment, a first modulating means which reads out the two kinds of bit allocation and transmission power allocation memorized at said first memorizing means and allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, by making the bit rate of the data transmission implementing during the period that said noise becomes large at said counter communication equipment higher than the bit rate of the data transmission implementing during the period that said noise becomes large at said apparatus for multi-carrier transmission.
According to a twenty fifth aspect of the peresent invention, in the twenty third aspect, said apparatus for multi-carrier transmission provides a second memorizing means which memorizes the bit allocation allocating to each carrier of said second frequency band and transmission power allocation using for each carrier of said second frequency band transmitted from said counter communication equipment during the period that said noise is large at said apparatus for multi-carrier transmission and memorizes the bit allocation allocating to each carrier of said second frequency band and transmission power allocation using for each carrier of said second frequency band during the period that said noise is large at said counter communication equipment, and a receiving means which includes a demodulating means that reads out the two kinds of bit allocation and transmission power allocation from said second memorizing means and demodulates the data transmitted from said counter communication equipment, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated at said counter communication equipment corresponding to the changing timing of noise level.
According to a twenty sixth aspect of the present invention, in the twenty fifth aspect, said apparatus for multi-carrier transmission provides a first filter means which removes side lobes generated at said second frequency band from the carrier of said first frequency band having the data, at the back position of said transmitting means, and a second filter means which removes side lobes generated at said first frequency band from the carrier of said second frequency band transmitted from said counter communication equipment, at the front position of said receiving means.
According to a twenty seventh aspect of the present invention, at an apparatus for multi-carrier transmission which implements the data transmission using the multi-carrier under the noise environment that the changing timing of noise level is known, said apparatus for multi-carrier transmission provides a first temporarily memorizing means for memorizing the data transmitted from external equipment temporarily a first memorizing means which memorizes the two kinds of the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the first frequency band transmitting the data, at the period that said noise is large at said apparatus for multi-carrier transmission and at the period that said noise is large at said counter communication equipment, a first modulating means which reads out the two kinds of bit allocation and transmission power allocation memorized in said first memorizing means and also reads out the data memorized in said first temporarily memorizing means, and selects the bit allocation allocating to said each carrier and transmission power allocation using for said each carrier of said first frequency band corresponding to the noise level at the data transmission, and modulates the amplitude of said each carrier to the amplitude corresponding to the selected bit allocation and transmission power allocation and the order of bits of the data allocating to said each carrier, an IFFT (inverse fast Fourier transform) means which adds tip each carrier of said first frequency band modulated the amplitude at said first modulating means and outputs the voltage value expressed in digital form, a transmitting means providing a DAC (digital to analog converter) means which converts the voltage value expressed in digital form outputted from said IFFT means to analog signals and outputs to a loop, and a first filter means which removes side lobes generated at said second frequency band by the carrier of said first frequency band outputted to the loop by said DAC means, and allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, by making the bit rate during the period that said noise is large at said counter communication equipment higher than the bit rate during the period that said noise is large at said apparatus for multi-carrier transmission, by said modulating means.
According to a twenty eighth aspect of the present invention, in the twenty seventh aspect, said apparatus for multi-carrier transmission provides an ADC (analog to digital converter) means which converts analog signals transmitted from said counter communication equipment using the carrier of said second frequency band to the voltage value expressed in digital form, a FFT (fast Fourier transform) means which implements the fast Fourier transform to said voltage value expressed in digital form from said ADC means and takes out each carrier whose amplitude is modulated of said second frequency band, a second memorizing means which memorizes the two kinds of bit allocation allocated to each carrier and transmission power allocation used for each carrier of said second frequency band transmitting from said counter communication equipment, at the period that said noise is large at said apparatus for multi-carrier transmission and at the period that said noise is large at said counter communication equipment, a demodulating means which reads out the two kinds of the bit allocation and transmission power allocation from said second memorizing means and takes out the data allocated to each carrier of said second frequency band from said FFT means, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at said counter communication equipment, a receiving means providing a second temporarily memorizing means which temporarily memorizes the data taken out by said demodulating means, in order to make the output amount of data a constant value, and a second filter means which removes side lobes generated at said first frequency band by each carrier of said second frequency band transmitted from said counter communication equipment, at the front position of said receiving means.
According to a twenty ninth aspect of the present invention, in the twenty third aspect, said first frequency band is a high frequency band and said second frequency band is a low frequency band.
According to a thirtieth of the present invention, in the twenty third aspect, said first frequency band is a low frequency band and said second frequency band is a high frequency band.
An apparatus for multi-carrier transmission of the present invention implements the data transmission from the apparatus for multi-carrier transmission to the counter communication equipment using the first frequency band and implements the data transmission from the counter communication equipment to the apparatus for multi-carrier transmission using the second frequency band. The bit allocation is allocated to each carrier of the first frequency band, by making the bit rate of the data transmission implementing during the period that the noise becomes large at the counter communication equipment higher than bit rate of the data transmission implementing during the period that the noise becomes large at the apparatus for multi-carrier transmission. With this, the present invention can improve the communication performance largely under the noise environment of the changing noise level, securing the compatibility with the existing communication systems using the frequency division. The frequency division system is used for the data transmission, therefore the mutual cross-talk noise does not exist and a complex apparatus such as an echo canceler is not needed to be installed.
The bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data during the period that the noise is large at the apparatus for multi-carrier transmission and the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data during the period that the noise is large a the counter communication equipment are memorized. The bit allocation to the carrier of the first frequency band is allocated, by making the bit rate of the data transmission at the period that the noise becomes large at the counter communication equipment higher than the bit rate of the data transmission at the period that the noise becomes large at the apparatus for multi-carrier transmission. With this, the data transmission corresponding to the noise level can be implemented.
The bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitted from the counter communication equipment during the period that the noise is large at the apparatus for multi-carrier transmission and the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitted from the counter communication equipment during the period that the noise is large at the counter communication equipment are memorized. The signal transmitted from the counter communication equipment is demodulated by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation used corresponding to the changing timing of noise level at the counter communication equipment. With this, even the amount of data transmission from the counter communication equipment is changed by the change of noise level, the transmitted data can be demodulated corresponding to the change.
According to a thirty first aspect of the present invention, at a method for multi-carrier transmission at a system for multi-carrier transmission which implements data transmission using the multi-carrier between a first communication equipment and a second communication equipment interactively under the noise environment that the changing timing of noise level is known, said first communication equipment provides a switching process which switches the bit allocation allocating to each carrier of a first frequency band which transmits the data corresponding to the changing timing of noise level, an allocating process which allocates the data to each carrier of said first frequency band corresponding to the switched bits allocation, and a first data transmitting process including a transmitting process which transmits each carrier allocated data of said first frequency band to said second communication equipment. And said second communication equipment, provides a switching process which switches the bit allocation allocating to each carrier of a second frequency band which transmits the data corresponding to the changing timing of noise level, an allocating process which allocates the data to each carrier of said second frequency band corresponding to the switched bits allocation, and a second data transmitting process including a transmitting process which transmits each carrier allocated data of said second frequency band to said first communication equipment. And said method for multi-carrier transmission, at the period that the noise is large at the data transmission of a first direction from said first communication equipment to said second communication equipment, makes the bit rate of the data transmission of said second direction from said second communication equipment to said first communication equipment using said second frequency band higher than the bit rate of the data transmission of said first direction from said first communication equipment to said second communication equipment using said first frequency band.
According to a thirty second aspect of the present invention, in the thirty first aspect, said method for multi-carrier transmission, at the period that the noise generated at the data transmission to the second direction is large, makes the bit rate of the data transmission to said first direction using said first frequency band higher than the bit rate of the data transmission to said second direction using said second frequency band.
According to a thirty third aspect of the present invention, in the thirty first aspect, said first data transmitting process allocates the data to each carrier of said first frequency band, by making the bit rate during the period that the noise generated at the data transmission to said second direction is large higher than the bit rate during the period that the noise generated at the data transmission to said first direction is large and implements the data transmission.
According to a thirty fourth aspect of the present invention, in the thirty first aspect, said second data transmitting process allocates the data to each carrier of said second frequency band, by making the bit rate during the period that the noise generated at the data transmission to said first direction is large higher than the bit rate during the period that the noise generated at the data transmission to said second direction is large and implements the data transmission.
According to a thirty fifth aspect of the present invention, in the thirty first aspect, said first communication equipment provides a first pseudo-random signal generating process which generates pseudo-random signals allocated in sequence the data being predetermined pseudo-random order to each carrier of said first frequency band using for the data transmission to said first direction, and a first transmitting process which transmits said pseudo-random signals generated at said first pseudo-random signal generating process to said second communication equipment. And said second communication equipment, provides a first receiving process which receives said pseudo-random signals transmitted from said first communication equipment, a first SNR (signal to noise ratio) calculating process which calculates the SNR value of each carrier of said first frequency band using for the data transmission to said first direction, used said pseudo-random signals received at said first receiving process, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, a first bit and power allocation calculating process which calculates the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said first frequency band, by using said SNR value of each carrier calculated at said first SNR calculating process, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, a first memorizing process which memorizes the two kinds of bit allocation and transmission power allocation calculated at said first bit and power allocation calculating process, and a second transmitting process which transmits the two kinds of bit allocation and transmission power allocation calculated at said first bit and power allocation calculating process to said first communication equipment. And said first communication equipment provides a second receiving process which receives the two kinds of bit allocation and transmission power allocation transmitted form said second communication equipment, and a second memorizing process which memorizes said two kinds of bit allocation and transmission allocation received by said second receiving process, said first data transmitting process includes a first modulating process which allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, by making the bit rate at the period that the noise generated at the data transmission to said second direction is large higher than the bit rate at the period that the noise generated at the data transmission to said first direction is large corresponding to the changing timing of noise level, using the two kinds of bit allocation and transmission power allocation memorized by said second memorizing process.
According to a thirty sixth aspect of the present invention, in the thirty first aspect, said second communication equipment provides a second pseudo-random signal generating process which generates pseudo-random signals allocated in sequence the data being predetermined pseudo-random order to each carrier of said second frequency band using for the data transmission to said second direction, and a third transmitting process which transmits said pseudo-random signals generated at said second pseudo-random signal generating process to said first communication equipment. And said first communication equipment provides a third receiving process which receives said pseudo-random signals transmitted from said second communication equipment, a second SNR (signal to noise ratio) calculating process which calculates the SNR value of each carrier of said second frequency band using for the data transmission to said second direction, used said pseudo-random signals received at said third receiving process, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, a second bit and power allocation calculating process which calculates the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said second frequency band, by using said SNR value of each carrier calculated at said second SNR calculating process, at the period that the noise generated at the data transmission to said first direction is large and at the period that the noise generated at the data transmission to said second direction is large, a third memorizing process which memorizes the two kinds of bit allocation and transmission power allocation calculated at said second bit and power allocation calculating process, and a fourth transmitting process which transmits the two kinds of bit allocation and transmission power allocation calculated at said second bit and power allocation calculating process to said second communication equipment. And said second communication equipment, provides a fourth receiving process which receives the two kinds of bit allocation and transmission power allocation transmitted form said first communication equipment, and a fourth memorizing process which memorizes said two kinds of bit allocation and transmission power allocation received by said fourth receiving process. And said second data transmitting process includes a second modulating process which allocates the bit allocation and transmission power allocation to each carrier of said second frequency band, by making the bit rate at the period that the noise generated at the data transmission to said first direction is large higher than the bit rate at the period that the noise generated at the data transmission to said second direction is large corresponding to the changing timing of noise level, using the two kinds of bit allocation and transmission power allocation memorized by said fourth memorizing process.
According to a thirty seventh aspect of the present invention, in the thirty sixth aspect, said first communication equipment provides a first data receiving process including a first demodulating process which demodulates the data transmitted from said second communication equipment, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at said second communication equipment, using the two kinds of bit allocation and transmission power allocation memorized by said third memorizing process.
According to a thirty eighth aspect of the present invention, in the thirty fifth aspect, said second communication equipment provides a second data receiving process including a second demodulating process which demodulates the data transmitted from said first communication equipment, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at said first communication equipment, using the two kinds of bit allocation and transmission power allocation memorized by said first memorizing process.
According to a thirty ninth aspect of the present invention, in the thirty first aspect, said first data transmitting process provides a first temporarily memorizing process for memorizing the data transmitted from external equipment temporarily, a first reading out process which reads out the two kinds of bit allocation and transmission power allocation memorized at said first memorizing process, a first selecting process which selects the bit allocation allocating to each carrier and transmission power allocation using for said each carrier of said first frequency band from the two kinds of bit allocation and transmission power allocation read out by said first reading out process, corresponding to the changing timing of noise level, a first modulating process which modulates the amplitude of each carrier of said first frequency band to the amplitude corresponding to the selected bit allocation and transmission power allocation and the order of bits of the data allocating to said each carrier, a first IFFT (inverse fast Fourier transform) process which adds up each carrier of said first frequency band modulated the amplitude at said first modulating process and outputs the voltage value expressed in digital form, a first DAC (digital to analog converter) process which converts the voltage value expressed in digital form outputted from said first IFFT process to analog signals and outputs to a loop, and a first filter process which removes side lobes generated at said second frequency band by the carrier of said first frequency band outputted to the loop by said first DAC process.
According to a fortieth aspect of the present invention, in the thirty first aspect, said second data transmitting process provides a second temporarily memorizing process for memorizing the data transmitted from external equipment temporarily, a second reading out process which reads out the two kinds of bit allocation and transmission power allocation memorized at said second memorizing process, a second selecting process which selects the bit allocation allocating to each carrier and transmission power allocation using for said each carrier of said second frequency band from the two kinds of bit allocation and transmission power allocation read out by said second reading out process, corresponding to the changing timing of noise level, a second modulating process which modulates the amplitude of each carrier of said second frequency band to the amplitude corresponding to the selected bit allocation and transmission power allocation and the order of bits of the data allocating to said each carrier, a second IFFT (inverse fast Fourier transform) process which adds up each carrier of said second frequency band modulated the amplitude at said second modulating process and outputs the voltage value expressed in digital form, a second DAC (digital to analog converter) process which converts the voltage value expressed in digital form outputted from said second IFFT process to analog signals and outputs to a loop, and a second filter process which removes side lobes generated at said first frequency band by the carrier of said second frequency band outputted to the loop by said second DAC process.
According to a forty first aspect of the present invention, in the thirty seventh aspect, said first data receiving process provides a third filter process which removes side lobes generated at said first frequency band by each carrier of said second frequency band transmitted from said second communication equipment, a first ADC (analog to digital converter) process which converts analog signals transmitted from said second communication equipment using the carrier of said second frequency band to the voltage value expressed in digital form, a first FFT (fast Fourier transform) process which implements the fast Fourier transform to said voltage value expressed in digital form from said first ADC process and takes out each carrier whose amplitude is modulated of said second frequency band, a third reading out process which reads out the two kinds of bit allocation and transmission power allocation memorized at said third memorizing process, a third selecting process which selects the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the noise level generated at the data transmission at said second communication equipment from the two kinds of bit allocation and transmission power allocation read out by said third reading out process, a first demodulating process which takes out the data, allocated to each carrier of said second frequency band, whose amplitude is modulated taken out at said first FFT process, by using the two kinds of bit allocation and transmission power allocation read out by said third reading out process, and a third temporarily memorizing process which memorizes the data taken out from said first demodulating process temporarily, in order to make the output amount of data a constant value.
According to a forty second aspect of the present invention, in the thirty eighth aspect, said second data receiving process provides a fourth filter process which removes side lobes generated at said second frequency band by each carrier of said first frequency band transmitted from said first communication equipment, a second ADC (analog to digital converter) process which converts analog signals transmitted from said first communication equipment using the carrier of said first frequency band to the voltage value expressed in digital form, a second FFT (fast Fourier transform) process which implements the fast Fourier transform to said voltage value expressed in digital form from said second ADC process and takes out each carrier whose amplitude is modulated of said first frequency band, a fourth reading out process which reads out the two kinds of bit allocation and transmission power allocation memorized at said first memorizing process, a fourth selecting process which selects the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the noise level generated at the data transmission at said first communication equipment from the two kinds of bit allocation and transmission power allocation read out by said fourth reading out process, and a second demodulating process which takes out the data, allocated to each carrier of said first frequency band, whose amplitude is modulated taken out at said second FFT process, by using the two kinds of bit allocation and transmission power allocation read out by said fourth reading out process, and a fourth temporarily memorizing process which memorizes the data taken out from said second demodulating process temporarily, in order to make the output amount of data a constant value.
According to a forty third aspect of the present invention, in the thirty eighth aspect, said first communication equipment provides a signal synchronized with noise generating process which generates a signal synchronized with noise which makes the amplitude of the designated carrier change, by synchronizing with the changing timing of noise level, and a fifth transmitting process which transmits the signal synchronized with noise generated at said signal synchronized with noise generating process to said second communication equipment, and said second communication equipment provides a fifth receiving process which receives said signal synchronized with noise transmitted from said first communication equipment, a timing detecting process which detects the changing timing of noise level by the change of the amplitude of said designated carrier received at said fifth receiving process, and a bit and power allocation selecting process which implements the designation of the bit allocation and transmission power allocation using for the data transmission corresponding to the noise level, from the two kinds of bit allocation and transmission power allocation memorized in said fourth memorizing process to said second modulating process, by the changing timing of noise level detected by said timing detecting process, and designates the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation used corresponding to the noise level at said first communication equipment from the two kinds of bit allocation and transmission power allocation memorized in said first memorizing process to said second demodulating process, to said second demodulating process.
According to a forty fourth aspect of the present invention, in the thirty first aspect, said first frequency band is a high frequency band and said second frequency band is a low frequency band.
According to a forty fifth aspect of the present invention, in the thirty first aspect, said first frequency band is a low frequency band and said second frequency band is a high frequency band.
A method for multi-carrier transmission of the present invention separates the frequency band using for the data transmission to the first direction and the frequency band using for the data transmission to the second direction. During the period that the noise generated at the data transmission to the first direction is large, the bit rate of the transmission to the second direction using the second frequency band is made higher than the bit rate of the transmission to the first direction using the first frequency band. During the period that the noise generated at the data transmission to the second direction is large, the bit rate of the transmission to the first direction using the first frequency band is made higher than the bit rate of the transmission to the second direction using the second frequency band. With this, the present invention can improve the communication performance largely under the noise environment of the changing noise level, securing the compatibility with the existing communication systems using the frequency division system. The frequency bands used for the data transmission to the first direction and the second direction are separated, therefore the mutual cross-talk noise does not exist and a complex apparatus such as an echo canceler is not needed to be installed.
At the first communication equipment, the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data to the first direction, at the period that the noise generated at the data transmission to the first direction is large and the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data to the first direction, at the period that the noise generated at the data transmission to the second direction is large are memorized. The bit allocation to the carrier of the first frequency band is allocated, by making the bit rate at the period that the noise generated at the data transmission to the second direction higher than the bit rate at the period that the noise generated at the data transmission to the first direction. With this, the transmission capacity to the first direction is secured under the noise environment of the changing noise level.
At the second communication equipment, the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band which transmits the data to the second direction, at the period that the noise generated at the data transmission to the first direction is large and the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band which transmits the data to the second direction, at the period that the noise generated at the data transmission to the second direction is large are memorized. The bit allocation to the carrier of the second frequency band is allocated, by making the bit rate at the period that the noise generated at the data transmission to the first direction is large higher than the bit rate at the period that the noise generated at the data transmission to the second direction is large. With this, the transmission capacity to the second direction is secured under the noise environment of the changing noise level.
At the first communication equipment, the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitting from the second communication equipment, at the period that the noise generated at the data transmission to the second direction is large, and the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitting from the second communication equipment, at the period that the noise generated at the data transmission to the first direction is large are memorized. The data transmitted from the second communication equipment are demodulated using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at the second communication equipment from the memorized two kinds of bit allocation and transmission power allocation. With this, even the transmission capacity of the data transmitting from the second communication equipment is changed by the change of noise level, the data can be demodulated at the first communication equipment.
At the second communication equipment, the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band transmitting from the first communication equipment, at the period that the noise generated at the data transmission to the second direction is large, and the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band transmitting from the first communication equipment, at the period that the noise generated at the data transmission to the first direction is large are memorized. The data transmitted from the first communication equipment are demodulated using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the noise cycle changing cyclically at the first communication equipment from the memorized two kinds of bit allocation and transmission power allocation. With this, even the transmission capacity of the data transmitting from the second communication equipment is changed by the change of noise level, the data can be demodulated at the second communication equipment.
At the second communication equipment, the pseudo-random signal allocated in sequence data being the predetermined pseudo-random order is generated to each carrier of the second frequency band using for the data transmission of the second direction and is transmitted to the first communication equipment. At the first communication equipment, the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the second frequency band is calculated by using this pseudo-random signal. With this, the bit allocation and transmission power allocation corresponding to the noise level can be calculated.
At the first communication equipment, the pseudo-random signal allocated in sequence data being the predetermined pseudo-random order is generated to each carrier of the first frequency band using for the data transmission of the first direction and is transmitted to the second communication equipment. At the second communication equipment, the bit allocation allocating to each carrier and transmission power allocation using for each carrier of the first frequency band is calculated by using this pseudo-random signal. With this, the bit allocation and transmission power allocation corresponding to the noise level can be calculated.
According to a forty sixth aspect of the present invention, a method for multi-carrier transmission under the noise environment that the changing timing of noise level is known provides a bit allocation switching process which switches the bit allocation allocating to each carrier of a first frequency band corresponding to the changing timing of noise level, at an apparatus for multi-carrier transmission implementing the data transmission using said first frequency band, an allocating process which allocates data to each carrier of said first frequency band, by using the switched bit allocation, and a transmitting process including a carrier transmitting process which transmits each carrier of said first frequency band allocated data to a counter communication equipment. And the method makes the bit rate of the data transmission implementing at the period that the noise level becomes large at said counter communication equipment higher than the bit rate of the data transmission implementing at the period that the noise level becomes large at said apparatus for multi-carrier transmission.
According to a forty seventh aspect of the present invention, in the forty sixth aspect, said transmitting process provides a first reading out process which reads out the two kinds of bit allocation and transmission power allocation from a first memorizing process which memorized the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said first frequency band transmitting data at the period that said noise is large at said apparatus for multi-carrier transmission and the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said first frequency band transmitting data at the period that said noise is large at said counter communication equipment, a first selecting process which switches the two kinds of bit allocation and transmission power allocation read out from said first reading out process, corresponding to the changing timing of noise level, and a modulating process which allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, using the bit allocation and transmission power allocation selected by said first selecting process, by making the bit rate of the data transmission implementing at the period that said noise becomes large at said counter communication equipment higher than the bit rate of the data transmission implementing at the period that said noise becomes large at said apparatus for multi-carrier transmission.
According to a forty eighth aspect of the present invention, in the forty sixth aspect, a second reading out process which reads out the two kinds of bit allocation and transmission power allocation from a second memorizing process which memorized the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said second frequency band transmitting data at the period that said noise is large at said apparatus for multi-carrier transmission and the bit allocation allocating to each carrier and transmission power allocation using for each carrier of said second frequency band transmitting data at the period that said noise is large at said counter communication equipment, a second selecting process which switches the two kinds of bit allocation and transmission power allocation read out from said second reading out process, corresponding to the changing timing of noise level, and a receiving process including a demodulating process which takes out the data from each carrier of said second frequency band transmitted from said counter communication equipment, using the bit allocation and transmission power allocation selected by said second selecting process.
According to a forty ninth aspect of the present invention, in the forty sixth aspect, said transmitting process provides a first temporarily memorizing process for memorizing the data transmitted from external equipment temporarily, a first reading out process which reads out the data to be transmitted from said first temporarily memorizing process and the two kinds of bit allocation allocating to each carrier and transmission power allocation using for said each carrier of said first frequency band transmitting the data from said first memorizing process, at the period that the noise is large at said apparatus for multi-carrier transmission and at the period that the noise is large at said counter communication equipment, a first selecting process which selects the bit allocation allocating to each carrier and transmission power allocation using for said each carrier of said first frequency band from the two kinds of bit allocation and transmission power allocation read out by said first reading out process, corresponding to the changing timing of noise level, a modulating process which modulates the amplitude of each carrier to the amplitude corresponding to the bit allocation and transmission power allocation selected by said first selecting process and the order of bits of the data allocating to said each carrier read out from said first selecting process, an IFFT (inverse fast Fourier transform) process which adds up each carrier of said first frequency band modulated the amplitude at said modulating process and outputs the voltage value expressed in digital form, a DAC (digital to analog converter) process which converts the voltage value expressed in digital form outputted from said IFFT process to analog signals and outputs to a loop, and a first filter process which removes side lobes generated at said second frequency band by the carrier of said first frequency band outputted to the loop by said DAC process. And the method allocates the bit allocation and transmission power allocation to each carrier of said first frequency band, by making the bit rate at the period that said noise is large at said counter communication equipment higher than the bit rate at the period that said noise is large at said apparatus for multi-carrier transmission, corresponding to the changing timing of noise level.
According to a fiftieth aspect of the present invention, in the forty eighth aspect, said first receiving process provides a second filter process which removes side lobes generated at said first frequency band by each carrier of said second frequency band transmitted from said counter communication equipment, provided at the front position of said receiving process, an ADC (analog to digital converter) process which converts analog signals transmitted from said counter communication equipment using the carrier of said second frequency band to the voltage value expressed in digital form, a FFT (fast Fourier transform) process which implements the fast Fourier transform to said voltage value expressed in digital form from said ADC process and takes out each carrier whose amplitude is modulated of said second frequency band, a second reading out process which reads out the two kinds of bit allocation allocating to each carrier of said second frequency band and transmission power allocation using for said each carrier of said second frequency band, at the period that said noise is large at said apparatus for multi-carrier transmission and at the period that said noise is large at counter communication equipment, which are memorized at said second memorizing process, a demodulating process which takes out the data allocated to each carrier of said second frequency band from said FFT process, by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation allocated corresponding to the changing timing of noise level at said counter communication equipment, and a second temporarily memorizing process which memorizes the data taken out from said demodulating process temporarily, in order to make the output amount of data a constant value.
According to a fifty first aspect of the present invention, in the forty sixth aspect, said first frequency band is a high frequency band and said second frequency band is a low frequency band.
According to a fifty second aspect of the present invention, in the forty sixth aspect, said first frequency band is a low frequency band and said second frequency band is a high frequency band.
A method for multi-carrier transmission of the present invention implements the data transmission from the apparatus for multi-carrier transmission to the counter communication equipment using the first frequency band and implements the data transmission from the counter communication equipment to the apparatus for multi-carrier transmission using the second frequency band. The bit allocation is allocated to each carrier of the first frequency band, by making the bit rate of the data transmission implementing during the period that the noise becomes large at the counter communication equipment higher than bit rate of the data transmission implementing during the period that the noise becomes large at the apparatus for multi-carrier transmission. With this, the present invention can improve the communication performance largely under the noise environment of the changing noise level, securing the compatibility with the existing communication systems using the frequency division system. The frequency division system is used for the data transmission, therefore the mutual cross-talk noise does not exist.
The bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data during the period that the noise is large at the apparatus for multi-carrier transmission and the bit allocation allocating to each carrier of the first frequency band and transmission power allocation using for each carrier of the first frequency band which transmits the data during the period that the noise is large at the counter communication equipment are memorized. The bit allocation to the carrier of the first frequency band is allocated, by making the bit rate of the data transmission at the period that the noise becomes large at the counter communication equipment higher than the bit rate of the data transmission at the period that the noise becomes large at the apparatus for multi-carrier transmission. With this, the data transmission corresponding to the noise level can be implemented.
The bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitted from the counter communication equipment during the period that the noise is large at the apparatus for multi-carrier transmission and the bit allocation allocating to each carrier of the second frequency band and transmission power allocation using for each carrier of the second frequency band transmitted from the counter communication equipment during the period that the noise is large at the counter communication equipment are memorized. The signal transmitted from the counter communication equipment is demodulated by using the same bit allocation and transmission power allocation as the bit allocation and transmission power allocation used corresponding to the changing timing of noise level at the counter communication equipment. With this, even the amount of data transmission from the counter communication equipment is changed by the change of noise level, the transmitted data can be demodulated corresponding to the change.